What Are the Treatments for Black Widow Spider Bites?

The venom of a black widow spider (female) is a potent toxin to the nervous system, but you receive only a small amount of toxin with a spider bite, so you are rarely in danger of dying. However, you may experience a range of symptoms, including severe pain, sweating, headache, itching, salivating, chills and high blood pressure. Severe cases (especially in children) can cause shock and coma.

Medications

• According to Mitchell and Medzon in Introduction to Emergency Medicine, initially you may only have slight swelling about the site of the spider bite. However, about 30 to 90 minutes after receiving a black widow bite, you may start to feel severe muscle cramping and pain in your limbs and back that spreads to the chest from bites on the upper part of the body or to the abdomen from bites on the legs. Your symptoms may be similar to an attack of appendicitis. Treatment comprises analgesia (pain medication), often with narcotics, to relieve the severe pain and muscle relaxants, such as benzodiazepine, to relieve the cramping. You must be observed carefully because in rare cases muscle cramping can progress to paralysis. While most symptoms usually subside in 4 to 5 days, you may have some pain in your muscles for the next 2 to 3 weeks.

Antivenin

• Lactrodectus Mactans (black widow) antivenin (also called antivenom) is available to neutralize the venom but is usually used only for those over age 16 or those at high risk, such as people with severe hypertension or respiratory disease and pregnant women (as the cramping can cause miscarriage). If you received a large dose of venom with the bite and are developing severe symptoms, you may also need antivenin.

  According to Drugs.com, antivenin is prepared with horse serum, so there is a danger of severe allergic (anaphylactic) reaction with shock, shortness of breath and swelling. Thus, you will probably receive an antihistamine drug before the antivenin to prevent or reduce an allergic response. The antivenin should reduce your symptoms in 1 or 2 days, but you may feel weak with muscle aches for about 10 days, and you may have a delayed severe allergic reaction (serum sickness) up to two weeks after administration.

Considerations

• If you receive a spider bite, it's very important to try to find the spider and bring it to the doctor in a container so it can be properly identified because antivenin is specific to black widows, and most other venomous spiders cause a different type of local reaction, requiring different treatment. Additionally, many spider bites are "dry" and without venom, so you may receive a bite but not have the typical systemic reaction.

  Because of the side effects of antivenin, the physician may not give antivenin without observing you for up to an hour to see if you are developing severe symptoms although the antivenin is more effective if given early. If you have had any reaction to horse products, you may need sensitivity tests before administration of the antivenin, and this can delay administration.